Landing Dispersion Results - Global Hawk Auto-land System

Abstract

The Global Hawk Unmanned Aerial Vehicle was conceived in 1995 by DARPA and its primary contractor, Teledyne Ryan Aeronautical (now part of the Northrop Grumman Corporation) as an airborne reconnaissance platform for the United States armed forces. The fleet consists of 4 aircraft, with another one currently being built and several more in the production pipeline. The aircraft is capable of flying 1200 nautical miles to an area of interest, stay aloft for 24 hours taking reconnaissance data over a 40,000 square mile target area and then flying back 1200 nautical miles to its operating base. The aircraft has successfully completed its military utility assessment, and has been approved to enter into an engineering manufacturing development phase and for low-rate production. The original Global Hawk navigation system utilized a combination of Litton’s LN-100G and LN-211G navigation systems. This configuration has been previously described in a paper presented in 1999 to the Institute of Navigation GPS conference, and in an article published in GPS World. Global Hawk's primary navigation system has been upgraded to utilize the Kearfott KN-4072 INS/GPS in place of the Litton LN211Gs (the LN-100Gs are still used for sensor reference). The primary driver for Global Hawk’s navigation system performance was driven by the need to autonomously taxi, takeoff and land at standard air force bases. Data, from a number of UAV flights with the Kearfott navigation system, were analyzed and shows that the landing dispersion meets the accuracy requirements for landings, and the navigation accuracy with DGPS aiding 1 Copyright  2002, the American Institute of Aeronautics and Astronautics Inc. All rights reserved. meets the requirements for taxi and takeoff. This paper will discuss the updated navigation system architecture, along with presenting results of the analysis of the navigation system performance.